CN1492612A - Spectrum spreading communication system using single spread spectrum code - Google Patents

Spectrum spreading communication system using single spread spectrum code Download PDF

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Publication number
CN1492612A
CN1492612A CNA021602646A CN02160264A CN1492612A CN 1492612 A CN1492612 A CN 1492612A CN A021602646 A CNA021602646 A CN A021602646A CN 02160264 A CN02160264 A CN 02160264A CN 1492612 A CN1492612 A CN 1492612A
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mobile radio
data
spread spectrum
path
signal
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CN1321505C (en
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近藤毅幸
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NEC Corp
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NEC Corp
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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69Spread spectrum techniques
    • H04B1/707Spread spectrum techniques using direct sequence modulation
    • H04B1/7097Interference-related aspects
    • H04B1/711Interference-related aspects the interference being multi-path interference
    • H04B1/7115Constructive combining of multi-path signals, i.e. RAKE receivers
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69Spread spectrum techniques
    • H04B1/707Spread spectrum techniques using direct sequence modulation
    • H04B1/709Correlator structure
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69Spread spectrum techniques
    • H04B1/707Spread spectrum techniques using direct sequence modulation
    • H04B1/7097Interference-related aspects
    • H04B1/7103Interference-related aspects the interference being multiple access interference
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69Spread spectrum techniques
    • H04B1/707Spread spectrum techniques using direct sequence modulation
    • H04B1/7097Interference-related aspects
    • H04B1/711Interference-related aspects the interference being multi-path interference
    • H04B1/7113Determination of path profile
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69Spread spectrum techniques
    • H04B1/707Spread spectrum techniques using direct sequence modulation
    • H04B1/7097Interference-related aspects
    • H04B1/711Interference-related aspects the interference being multi-path interference
    • H04B1/7115Constructive combining of multi-path signals, i.e. RAKE receivers
    • H04B1/7117Selection, re-selection, allocation or re-allocation of paths to fingers, e.g. timing offset control of allocated fingers
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69Spread spectrum techniques
    • H04B1/707Spread spectrum techniques using direct sequence modulation
    • H04B2001/70706Spread spectrum techniques using direct sequence modulation using a code tracking loop, e.g. a delay locked loop
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B2201/00Indexing scheme relating to details of transmission systems not covered by a single group of H04B3/00 - H04B13/00
    • H04B2201/69Orthogonal indexing scheme relating to spread spectrum techniques in general
    • H04B2201/707Orthogonal indexing scheme relating to spread spectrum techniques in general relating to direct sequence modulation
    • H04B2201/70701Orthogonal indexing scheme relating to spread spectrum techniques in general relating to direct sequence modulation featuring pilot assisted reception

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Synchronisation In Digital Transmission Systems (AREA)
  • Radio Relay Systems (AREA)

Abstract

A spectrum spreading communication system including a radio base station includes a receiving section, a correlation detecting section, a rake synthesizing section and a control section. The receiving section receives a radio signal to produce a digital burst signal. Transmission data of the radio signal respectively include different pilot patterns and data, are subjected to spectrum spreading using a single spreading code, and are transmitted on a same frequency band. The correlation detecting section performs a tracking operation to the burst signal for each of paths to produce a tracking resultant data. The paths are specified based on a path data.

Description

Adopt the spectrum spread communication system of single spreading code
Technical field
The present invention relates to a spectrum spread communication system, relate in particular to a spectrum spread communication system that is suitable on same frequency band, using simultaneously identical spreading code transmission random pulses string signal from a plurality of mobile radio stations to a wireless base station.
Background technology
A kind of existing mobile communication system that adopts this type spectrum spread communication system is disclosed in Japanese patent application (spy opens flat 5-227124).To be an explanation be used in a receiving system block diagram in the cdma communication system as prior art to Fig. 1.
This cdma communication system is made up of a wireless base station 300 and a plurality of mobile radio station 200.Communication between a frequency spreading code division dispensing wireless base station 300 and each mobile radio station 200 is so that can realize two-way communication.This wireless base station 300 merges based on the pilot signal of a short period coding P spread spectrum with based on the long period coding A corresponding with each mobile radio station 200, the data transfer signals of B and E spread spectrum, and a short period is set to a bit.This combined signal is transferred to mobile radio station 200.200 pairs of each mobile radio stations receive the long period coding A that data transfer signals is used respectively to distribute to mobile radio station, and C and E realize de-spread.Also have, each mobile radio station 200 utilizes respectively and sends long period coding B, and D and F spread spectrum data transmit signal.The 300 pairs of receptions in wireless base station data transfer signals is used the reception long period coding B corresponding to each mobile radio station respectively, and D and F realize de-spread.
In a kind of like this structure, be that generation sequential and each long period that is based upon short period coding P encoded A between the F synchronously.Also have, a time mark is included in the pilot signal, so that indicate the bit position of the long period coding of corresponding this pilot signal, makes it possible to separately this long period and is encoded to a plurality of groups and distribute them to give many mobile radio stations.Therefore, it is synchronous to utilize the frequency of short period coding to lead the very fast foundation of signal.Also have can the setting up according to the time mark that is included in the pilot signal synchronously of a corresponding group part of long period coding, so that can being set up easily and apace synchronously of this long period coding.Therefore, it is possible providing this cdma communication system to make it can distribute unique encoding to keep an access random function simultaneously to many mobile radio stations.
Yet, in a kind of like this technology that is published in Japanese patent application (spy opens flat 5-227124), need special control.That is, have one and be based upon synchronously between pilot signal and the data traffic signals, the insertion of life period mark with collect and the generation of mating the local flag of this time mark.Therefore, exist a size changing circuit to make the circuit complicated problems that becomes greatly.
Also have, in other prior art, identical spreading code of a plurality of portable terminal emissions.Suppose that the common spreading code of same time utilization that is received in of burst signal in these portable terminals realizes access request to a wireless base station, then signal separately is interfering with each other.
Also have, in this pulse train communication, be difficult to strictly be implemented in indispensable through-put power control in the spectrum spread communication system.
Owing to these reasons, the dissipation of the signal level that is received by the wireless base station becomes big so that a time-delay distribution multilated that is used to detect the path.As a result, in the problem that exists the path detection ability to degenerate.
Moreover even an initial synchronisation correlation unit (searcher) is caught burst signal from mobile radio station, the mobile radio station in each path can not easily be determined.Therefore, have a problem that can not realize best that Rake merges, it is the technology of improving communication quality significantly, particularly spectrum spread communication system that this Rake merges.
Except the above-mentioned list of references of mentioning, also have a kind of spectrum spread communication system to be published in the Japanese patent application (spy opens clear 56-102143).In this list of references, baseband signal is by adding the data that will launch and a pilot signal forms.Receiving on one side, this pilot signal is detected so that set up synchronously.
Also have, a transmission signals system is published in the Japanese patent application (spy opens clear 59-50603).In this list of references, a synchronizing signal transmits through the digital phase modulation communication line with transmitting.After receiving, the control of an antenna is to utilize the synchronizing signal as its identification reference signal to realize.
Also have, an automatic telephone system is published in the Japanese patent application (spy opens clear 63-202144).In this list of references, a plurality of communication channels are with frequency partition.A spectrum expanding communication is to be used to the circuit control that a circuit control channel is realized communication channel.Spread spectrum code sequence based on the circuit control channel is corresponding to a mobile radio station telephone number.
Also have, the receiving equipment in spectrum spread communication system is published in the Japanese patent application (spy opens flat 2-39139).In this list of references, receiving equipment is made up of one first quasi-noise coding generation unit, a correlation detector, a clock generating unit, second quasi-noise coding generation unit, a control unit and a demodulating unit.First quasi-noise coding generation unit produces first quasi-noise coding that all the time input spectrum expansion received signal is changed phase place.Correlation detector always detects the correlation behavior between this spread spectrum received signal and first quasi-noise coding, so that detect the state of spread spectrum received signal.Clock generating unit produces a clock so that the result who detects according to correlation detector controls first quasi-noise coding generation unit, and the quasi-noise encoding phase of winning is changed facing to the spread spectrum received signal all the time.Second quasi-noise coding generation unit produces one second quasi-noise coding.Control unit is encoded from second quasi-noise of second quasi-noise coding generation unit according to the information Control that correlation unit detects, and makes this spread spectrum received signal consistent with second quasi-noise coding.Second quasi-noise coding that demodulating unit is controlled according to control unit is realized the rectification to the spread spectrum received signal.
Also have, a receiving equipment in the spectrum spread communication system is published in the Japanese patent application (spy opens flat 6-152564).In this list of references, the existence of (step 111) busy tone carrier wave or do not exist before packets of information transmits detects.When detecting " L " level at the fixed time, execution in step 112.Also have, the signal from this station output is obtained the result with the signal comparison of exporting from another station so that understand the channel at this station.When this signal when the channel cycle of obtaining becomes " H " level, channel obtains and is cancelled, and carries out a receiving course then.(step 112) shift register is exported the busy tone of its authentication code as data.(step 113 and step 114) determines whether that all busy tone data all are transmitted, and when relative B station other signal of comparative degree remains on channel when obtaining " L " level state in cycle, a PN coding transmits continuously according to a PN coding schedule.Therefore, frequency band can effectively utilize and a plurality of communication station can communicate with one another in a spectrum spread communication system simultaneously.
Also have, a spectrum spread communication system is published in the Japanese patent application (spy opens flat 7-30514).In this list of references, 1 pair one of a matched filter realizes that the received signal R1 of spread spectrum carries out the inverse frequency spectrum expansion, produces a pulse train R2 with an inverse expansion coding R2.2 one of the estimation response of transmission path evaluation unit comprise the transmission characteristic in path of multi-path of pilot signal R1a of received signal R2 so that produce braning factor R4 (R4a), and a transversal filter 3 utilizes braning factor R4 to carry out tap weights to produce the maximum ratio composite signal R5 of this pulse train R3.A multipath disturbs reproduction units 5 in response to braning factor R4a, restituted signal R6 and inverse expansion coding R2 regeneration multipath interference signal R8.A subtrator 7 has deducted interference signal by delay cell 6 from the time-delay composite signal R5a that composite signal R5 delays time from one.A determining unit 8 determines that a cut signal R9 is so that export a restituted signal R10.Therefore, the multipath interference signal of a received spectrum spread signal is removed on base band.
Also have, the wireless communication system of a CDMA/TDD system is published in the Japanese patent application (spy opens flat 7-221700).In this list of references, except the structure of the wireless communication system of existing CDMA/TDD system, wireless base station is also formed to the device 16 of mobile radio station by being used for producing having for each mobile radio station with for the device 15 of the pilot signal of the constant transmission power level known to the mobile radio station and by a transmission path pilot signal.Also have, each mobile radio station also form with being used for according to the received power of the pilot signal of measuring by the device 19 that is used to measure the transmitting power that receives pilot signal by the device 8 of the transmitting power of power controlling amplifying circuit 10.
Also have, the wireless communication system of a CDMA/TDD system is published in the Japanese patent application (spy opens flat 7-226710).In this list of references, except the structure of the wireless communication system of existing CDMA/TDD system, wireless base station is also formed by being used for producing having for each mobile radio station and the single-tone generation device 26 giving the device 16 of mobile radio station and be used to be transmitted into mobile radio station all the time for the device 15 of the pilot signal of the constant transmission power level known to the mobile radio station, by a transmission path pilot signal, and a single-tone has single-frequency and constant transmit power.Also have, each mobile radio station also by the device 19 that is used to measure the transmitting power that receives pilot signal, be used to measure single-tone received power device 28 and be used for according to the received power of the single-tone of the received power of the pilot signal of measuring and measurement and the device 8 of the transmitting power of power controlling amplifying circuit 10 is formed.
Also have, the Rake receiving equipment of a direct spectrum spread communication system is published in the Japanese patent application (spy opens flat 7-231278).In this list of references, N path directly expand modulation signal S30 by first to N inverse expansion unit 50 1To 50 NReceive, use the first synchronous signal S30 of N signal S30 that differs from one another with the reception sequential then to N sequence spreading inverse expansion and demodulate reception.This demodulated data D40 1To D40 NSynthetic by a synthesis unit 51.Having the signal of maximum level of N signal S30 and the level difference between other signals is determined.When each level difference during greater than a predetermined threshold values T, control is to having level difference greater than from maximum level (for example, 50 N-2 '50 N-1 '50 N) the signal of the threshold values T inverse expansion device that carries out inverse expansion and demodulation be set to off status.
Summary of the invention
The present invention will realize addressing the above problem.Therefore, an object of the present invention is to provide a kind of spectrum spread communication system that can realize communication with high-quality, even a plurality of mobile radio station is visited a wireless base station with the pulse signal of same spread sign indicating number and same frequency band.
Another object of the present invention provides a kind of spectrum spread communication system, and it can be discerned, and a plurality of paths are feasible may carry out the Rake merging and improve communication quality.
In order to realize one aspect of the present invention, a kind of spectrum spread communication system of wireless base station that comprises comprises: one is used for receiving radio signals to produce the receiving element of a digital burst signal, wherein, the transmission data of radio signal comprise different pilot code types respectively, utilize single spreading code that data are carried out spread spectrum, and on a same frequency band, launch; One is used for the described burst signal of every paths is carried out the tracking operation to produce the coherent detection unit of tracking results data, described path is according to the path data appointment, and based on the one-component of the described tracking results Data Detection described burst signal relevant with the described spreading code of every paths; At each described pilot code type these described components from described coherent detection unit are carried out the Rake merge cells that Rake merges for one; And control unit, it is used for determining path candidate from described burst signal so that output is given described coherent detection unit corresponding to the described path data of described path candidate, and being used for controlling described Rake merge cells, the described Rake of carrying out correlated components for a plurality of paths of each described pilot code type merges.
Each described transmits data packets is drawn together an identifier data of a mobile radio station launching described transmission data, and described wireless base station also comprises and is used to decode from the signal of described Rake merge cells output and is used for extracting a data decoding unit of the moving station mark symbol data that are included in the decoded signal of specifying mobile radio station respectively.
Control unit comprises a plurality of searcher units that described pilot code type provides that are respectively, and each of wherein said a plurality of searcher units is determined bigger likelihood level between corresponding pilot code type and the described burst signal; And path control unit, it determines path candidate according to surpassing the described of described pilot code type than the maximum-likelihood level, described path data being exported to described coherent detection unit, and be used for controlling described Rake merge cells and for each described pilot code type these described components from described coherent detection unit carried out described Rake and merge.
Each searcher unit is carried out homophase and is determined to have the described path candidate of homophase addition result greatly mutually between a pilot code type component of coded sequence of the pilot code type of described correspondence and described burst signal.
In addition, control unit can comprise a searcher unit that is used for determining to have than the described path candidate of maximum-likelihood level between described spreading code and described burst signal; A plurality ofly be respectively the type detection unit that described pilot code type provides, each of wherein said a plurality of type detection unit is determined one of described pilot code type for each described path candidate; And path control unit, be used for exporting described path data and give described coherent detection unit, and be used for controlling described Rake merge cells and merge carry out described Rake from the described component of described coherent detection unit for each described pilot code type according to the pilot code type that detects by described a plurality of type detection unit.
Each of a plurality of type detection unit is carried out homophase and is determined to have the described path candidate of homophase addition result greatly mutually between a pilot code type component of coded sequence of the pilot code type of described correspondence and described burst signal.
In addition, the coherent detection unit comprises a plurality of tracking cell, each tracking cell is that the tracking operation is carried out so that produce the part of described tracking results data to described burst signal in a corresponding path in the described path, and a plurality of correlation units that provide for described a plurality of tracking cell, each correlation unit is the one-component that every paths detects the described burst signal relevant with described spreading code according to described tracking results data.
The coherent detection unit, described Rake merge cells, described control unit and described data decode unit are included in the spreading code decoding unit; And spectrum spread communication system also comprises a plurality of described spreading code decoding units that a plurality of described spreading codes provide that are respectively.
For realizing another aspect of the present invention, provide a kind of in the spectrum spread communication system that comprises a wireless base station and a plurality of mobile radio stations, a kind of communication means from a plurality of described mobile radio stations to described wireless base station may further comprise the steps:
On identical frequency band, transmit data as radio signal from described a plurality of mobile radio station emissions, wherein said transmission data comprise different pilot code type and data respectively, this different pilot code type is distributed to described a plurality of mobile radio station, and adopts single spreading code that described transmission data are carried out spread spectrum respectively by described a plurality of mobile radio stations;
Receive described radio signal to produce digital burst signal;
From described burst signal, determine path candidate producing the described path data of corresponding described path candidate,
Wherein determine between each described pilot code type and described burst signal than the maximum-likelihood level, and
Determine that than the maximum-likelihood level path candidate is to produce described path data according to surpassing the described of described pilot code type;
For every paths described burst signal is carried out the tracking operation to produce tracking results data, specify described path according to path data;
According to described tracking results data is the one-component that every paths detects the described burst signal relevant with described spreading code; And
Rake merges so that be communication generation Rake combined signal to carrying out from the described component of described coherent detection unit for each described pilot code type.
Description of drawings
Fig. 1 is a block diagram that existing spectrum spread communication system notion is shown;
Fig. 2 is a block diagram that a mobile communication system structure in the spectrum spread communication system of the present invention is shown;
Fig. 3 is a transmitter unit block diagram that a mobile radio station in the spectrum spread communication system of the present invention is shown;
Fig. 4 is one and illustrates in the spectrum spread communication system of the present invention from the diagrammatic sketch of the example of the signal format of mobile radio station emission;
Fig. 5 A is a short code figure, and Fig. 5 B-1 and 5B-2 are the diagrammatic sketch of pilot signal (PL) symbol, and Fig. 5 C-1 and 5C-2 are the diagrammatic sketch of the sign indicating number type determined from short code and PL symbol;
Fig. 6 is a block diagram that the receiving element structure of a wireless base station in the spectrum spread communication system is shown according to the first embodiment of the present invention;
Fig. 7 A-1 and 7A-2 are the diagrammatic sketch of a short code figure and a pilot signal (PL) symbol, Fig. 7 A-3 is the diagrammatic sketch of the sign indicating number type determined from short code and PL symbol, Fig. 7 B-1 and 7B-2 are the diagrammatic sketch of another short code figure and another pilot signal (PL) symbol, Fig. 7 B-3 is the diagrammatic sketch of another yard type of determining from short code and PL symbol, Fig. 7 C-1 is the diagrammatic sketch of the coding example of pilot signal searches device parts, Fig. 7 C-2 and 7C-3 are the diagrammatic sketch of the coding example of a received signal, the likelihood level of a correlated components, and Fig. 7 C-4 and 7C-5 are the diagrammatic sketch of the coding example of another received signal, and the likelihood level of another correlated components; And
Fig. 8 is a receiving element block diagram that wireless base station in the spectrum spread communication system is shown according to a second embodiment of the present invention.
Embodiment
Next, spectrum spread communication system of the present invention is described with reference to these accompanying drawings.
Fig. 2 is a block diagram that a mobile communication network structure in the spectrum spread communication system of the present invention is shown.In Fig. 2, this mobile communications network is connected to the public telephone line network network that a conduct has wire net now by a mobile communication system control assembly and a switch 100.This communication is undertaken by mobile communication system control assembly and switch 100 in mobile communications network and between mobile communications network and public telephone line network network.Notice that this mobile communication system control assembly and switch 100 are the equipment of switch that comprises a kind of control unit of the wireless base station 300 for a plurality of mobile communications networks of mobile communication and one control.Wireless base station 300 forms a wireless zone, provides the mobile communication service by the electromagnetic wave by wireless base station emission and reception to these mobile radio stations 200 in this zone.
Between wireless base station 300 and mobile radio station 200, adopt a kind of CDMA (code division multiple access) system communication system or a kind of spectrum spread communication system of being called.In this communication system, the distribution spreading code spread spectrum that will in identical frequency band, launch of the signal of an emission, and received signal is come de-spread at a receiving element with the same spread sign indicating number.
In spectrum spread communication system of the present invention, when these mobile radio stations 200 began request and packet with burst signal form emission calling, wireless base station 300 was visited randomly.In a kind of common spectrum spread communication system, each mobile radio station of frequency spreading code division dispensing moves as the service channel of a special use so that communicate by letter with other and keeps quadrature.This just as accepted call initiation requests from mobile radio station 200, on one side and with communication after communicating by letter in the destination.Yet, in the present invention, use the burst signal of same spreading code spread spectrum to be received by the receiving element of wireless base station.
That is to say that characteristics of the present invention are to distribute a pilot tone (PL) sign indicating number type for each mobile radio station 200.In advance the pilot code type being distributed and registering to these mobile radio stations 200 makes it might utilize a plurality of yards type code element identifications to have short code such as the gold code sequence and the walsh code sequences of orthogonality.For example, when the sign indicating number type quantity of pilot code type was 8, a pilot code type (0) was repeatedly distributed to mobile radio station to pilot code type (7) according to the identifier number of mobile radio station.Each mobile radio station just is added to the pilot code type that distributes in the emission data under the situation of transmitted pulse string signal.
Fig. 3 is a part-structure block diagram that the mobile radio station 200 relevant with the burst signal emission is shown.Fig. 4 shows the signal format of emission data in the frame emission.
This mobile radio station 200 is made up of 210, one analog to digital conversion unit of a transmitter, 220, one codings, 230, one coding units 240 of expanding element and a control unit 250.Under the situation of utilizing call initiation requests of packet transmission and random access, the above-mentioned pilot code type of coding unit 240 coding, the moving station mark symbol that comprises moving station mark number and emission data produces a frame emission under the control of control unit 250.The transmission frame of this coding is done spread spectrum by coding expanding element 230 and is handled.When mobile radio station entered the wireless-communication-capable area of wireless base station, at this moment usefulness spreading code was a burst transmissions spreading code of having circulated a notice of by an announcement channel from the wireless base station.Three kinds or four kinds of spreading codes or a kind of spreading code are under special circumstances only prepared in this wireless base station.Because carry out this burst transmission, control unit 250 provides the burst transmission spreading code of prenoticing to coding expanding element 230.Realized that by coding expanding element 230 transmission frame of spread spectrum offers digital to analog conversion unit 220 and does numeral (D)/simulation (A) conversion and export with form of electromagnetic wave from transmitter 210 then.
The example of the transmission frame of Shu Chu transmission signals is presented among Fig. 4 by this way.Also have, the example of pilot code type is presented at Fig. 5 A in 5C-2.
Next, the structure of wireless base station is described with reference to Fig. 6 in the spectrum spread communication system of the present invention.Fig. 6 is a part of block diagram of the receiving system of wireless base station in the communication system that the present patent application is shown.
Wireless base station 300 is by 310, one analog to digital conversion unit 320 of an antenna, and the spreading code decoding unit 400-I that provides for spreading code and have same structure forms to 400-H.The spreading code decoding unit 400-I that is used for spreading code A is made up of to 470-N to 460-N and pilot code type (PL) data decode unit 470-1 to 450-M, pilot code type (PL) data Rake merge cells 460-1 to 420-N, path control unit 430, a tracking cell 450-1 a spreading code A generation unit 410, pilot code type (PL) searcher unit 420-1.
These mobile radio stations 200-1 utilizes by using the burst transmission spreading code to comprising that pilot code type PL1 carries out spread spectrum to the burst signal of PLN and handles the message reference wireless base station 300 that obtains to 200-I.
In this wireless base station 300, burst signal is received by antenna 310, and the signal of this reception is subjected to analog/digital conversion in analog to digital conversion unit 320.Then, in spreading code decoding unit 400, carry out de-spread and handle, so that take out signal data.As the spreading code decoding unit, a plurality of spreading code decoding unit 400-1 are offered separately spreading code to 400-H.
As an example detailed structure of spreading code decoding unit is described, for the decoding unit 400-1 of a spreading code A of the burst signal that adopts spreading code A.
At first, spreading code generation unit 410 is handled for de-spread and is produced spreading code A.
Then, characteristics of the present invention be PL searcher unit 420-1 to N, PL Rake merge cells 460-1 to N and PL data decode unit 470-1 to N corresponding to the multiple above-mentioned PL sign indicating number type of preparing as system in advance.
These pulse signals are received and are offered analog to digital conversion unit 320 by antenna 310 and carry out analog/digital conversion, so that produce a digital received signal.Each pilot code type searcher unit 420-1 is to output spreading code A and the digital received signal of 420-N input from extended coding generation unit 410.In for the hunting zone of each pilot code type or sign indicating number type, pilot code type searcher unit is determined the likelihood level of a correlated components between spreading code A and digital received signal.Especially, this correlated components is the pilot code type component that will describe by the back, utilizes the coded sequence of each pilot code type of digital received signal and the locking phase Calais of spreading code A to determine.As a result, detect the multi-path or the path of received pulse string signal for each pilot code type.
Each pilot code type Rake (PL RAKE) merge cells 460-1 is that each pilot code type is carried out the Rake merging to the correlated components of multi-path to 460-N.Each bootmode (PL) data decode unit 470-1 is that the signal decoding of output and extraction were included in moving station mark symbol in the decoded signal after each PL sign indicating number type Rake was merged to the function of 470-N, to specify and output moving station mark numbering.
For other elements, be provided with these a plurality of tracking cell 440-1 to 440-M, each input in them is from the spreading code A of spreading code A generation unit 410 output and from the digital received signal of analog/digital conversion unit 320.This tracking cell is realized tracing process to a specified path.This tracing process is a process of following the tracks of the minor variations of the RX path sequential that produces, and this variation is owing to causing because mobile station location changes the variation of the signal propagation delay that produces between mobile radio station and wireless base station.
Each correlation unit 450-1 from the spreading code A of spreading code A generation unit 410 outputs and from the digital received signal of analog/digital conversion unit, and determines a correlated components between digital received signal and the spreading code A according to the output of corresponding tracking cell to 450-M input.The control that will describe after path control unit 430 is realized.
The path data that control unit 430 input pilot code type searcher unit 420-1 in path export to 420-N, and determine should realize following the tracks of the tracking cell 440-1 of processing to 440-M to the path.Also have, control unit 430 issuing commands in path give pilot code type Rake merge cells 460-1 to 460-N.Each pilot code type Rake merge cells 460-1 is connected to correlation unit 450-1 in the 450-M to 460-N, respond in the corresponding instruction, correlation unit is exported in the pilot code type Rake merge cells corresponding one with the path signal of identical PL sign indicating number type.
The work of the wireless base station 300 that constitutes by this way will be described below.
In Fig. 6, receive by antenna 310 to the burst signal of 200-I from mobile radio station 200-1, transform to digital form by analog to digital conversion unit 320 and offer spreading code A decoding unit 400-1 then.
In spreading code A decoding unit 400-1, each PL searcher unit 420-1 detects and exports one group of path candidate with a plurality of paths of big PL component homophase addition level as each pilot code type to N.Also have, pilot code type searcher unit calculates correlated components and coded sequence of a pilot code type part of digital received signal, as a spreading code A and result corresponding to the exclusive-OR operation of the pilot code type of the pilot code type searcher unit of region of search.Therefore, the distribution of pilot code type component homophase addition is confirmed as the possible level in path.Then, as to specifying spreading code, be spreading code A according to the path of the sequence detection predetermined quantity of big pilot code type component homophase addition in this example, and the path candidate of the pilot code type of appointment.The chip phase and the likelihood level of the path candidate that is detected to 420-N by each PL searcher unit 420-1 are sent to path control unit 430.
Fig. 7 A-1 is the detection schematic diagram that the correlated components that is realized by the PL searcher unit is shown to 7C-5.Two examples of pilot code type be presented at Fig. 7 A-1 to 7A-3 and 7B-1 to 7B-3.Note these figure and Fig. 5 A to 5C-2 show the same.Shown in pilot code type use the short coding of 4 chips of one-period and 4 code elements pilot code type code element as an example.The coded sequence of sign indicating number type No.0 is the coded sequence of determining according to a short coding " 1 ,-1 ,-1,1 " and a pilot code type code element " 1,1 ,-1 ,-1 ".Also have, the coded sequence of sign indicating number type No.1 is the coded sequence of determining according to a short coding " 1 ,-1 ,-1,1 " and a pilot code type code element " 1,1,1,1 ".
Now, suppose that pilot code type No.1 (PL1) searcher unit 420-1 has the coded sequence of Fig. 7 A-1 to the type of pilot code shown in the 7A-3.The principle that is used for determining the correlated components between the pilot code type coded sequence of each coded sequence of received signal and PL1 searcher unit 420-1 is presented at Fig. 7 C-1 to 7C-5.
As seeing to 7C-5 from Fig. 7 C-1, if the coded sequence of received signal is consistent with sign indicating number type No.0, when sequential was consistent each other, the correlated components of " 16 " was obtained, shown in Fig. 7 C-3.Yet, suppose the coded sequence difference of sign indicating number type, even sequential is consistent each other, the correlated components of " 0 " is obtained, shown in Fig. 7 C-5.In this way, each pilot code type searcher unit 420-1 is to 420-N identification and only extract the received signal that has with the identical PL sign indicating number of the PL sign indicating number type coded sequence type of pilot code type searcher unit.Therefore, detected as the chip phase of the peak value of multi-path.
Next, again with reference to figure 6, specifically describe pilot code type searcher unit 420-1 to the output of 420-N, path control unit 430, tracking cell 440-1 to 440-M, correlation unit 450-1 to 450-M and pilot code type (PL) Rake merge cells 460-1 to the work of 460-N.
In order to simplify description, suppose PL1, the pilot code type of PL2 and PL3 is distributed to three mobile radio station 200-1 respectively to 200-3.Also have, suppose that a spread spectrum process adopts the pulse signal of a spreading code A and an emission to realize.Also have, suppose each pilot code type searcher unit 420-1 to 420-N according to than the order detection #1 of maximum-likelihood level four peak values, so that will output to path control unit 430 with the likelihood level value corresponding to the chip phase in the path of peak value to #4.Further, suppose to provide 10 groups of tracking cell and correlation unit.In this case, (PL3) Shu Chu four peak value #1 are expressed as x1 respectively to x4 to the path of #4 for PL1, PL2, and y1 is to y4, and z1 is to z4 from pilot code type searcher unit separately as the result of above-mentioned pilot code type search.Also have, suppose to get the value of an indication in () corresponding to the likelihood level value of each peak value of spreading code A.
PL sign indicating number type #1 peak value #2 peak value #3 peak value #4 peak value
PL1 x1(1) x2(3) x3(6) x4(7)
PL2 y1(1) y2(5) y3(8) y4(10)
PL3 z1(1) z2(9) z3(11) z4(12)
Path control unit 430 according to these data to rearrange likelihood level value separately corresponding to the higher level value of spreading code A.
01 02 03 04 05 06 07 08 09 10 11 12
x1 y1 x2 z1 y2 x3 x4 y3 z2 y4 z3 z4
Now, because the set quantity of tracking cell and correlation unit is 10, path control unit 430 is selected 10 paths according to the order of higher level value, and the data of transmission expression 10 paths are given tracking cell separately then.
Order 01 02 03 04 05 06 07 08 09 10
Path x1 y1 x2 z1 y2 x3 x4 y3 z2 y4
That is, these instruction issues make tracking cell 440-1 follow the tracks of the path of x1, and tracking cell 440-2 follows the tracks of the path of y1, and tracking cell 440-1 follows the tracks of the path of x1, and tracking cell 440-3 follows the tracks of the path of x2 ..., tracking cell 440-10 follows the tracks of the path of y4.The correlation unit output of corresponding each tracking cell has the correlated components of the received signal of respective paths spreading code A.Path control unit 430 issuing commands give pilot code type Rake merge cells 460-1 to 460-3 so that corresponding identical PL sign indicating number type correlation unit 440-1 is connected to the pilot code type Rake merge cells of correspondence to one output among the 440-10.
Each pilot code type Rake merge cells 460-1 carries out Rake to 460-3 to the output signal of same paths and merges.That is, because correlation unit 450-1,450-3,450-6, the correlated components of the received signal in the path of 450-7 output pilot code type PL1 is so the output of each correlation unit all is connected to pilot code type Rake merge cells 460-1.Because relevant single 450-2,450-5,450-8,450-10 is at the correlated components of the path output received signal of pilot code type PL2, so the output of each correlation unit all is connected to pilot code type Rake merge cells 460-2.Also have, because correlation unit 450-4,450-9 is at the correlated components of the path output received signal of pilot code type PL3, so the output of each correlation unit all is connected to pilot code type Rake merge cells 460-3.
By correspondence separately pilot code type (PL) the data decode unit 470-1 of pilot code type decode to 470-3 and merge the signal that obtains by in each pilot code type Rake merge cells 460-1 to 460-3, carrying out Rake.As a result, the moving station mark data that are included in the decoded data are extracted and export as being the received signal of each mobile radio station appointment.
Like this, in spectrum spread communication system of the present invention, detect a plurality of paths (multi-path) that in pilot code type searcher unit, the spreading code A of each pilot code type had a correlated components.Extraction to the correlated components of the tracking operation of every paths and received signal is performed according to the path data that detects, therefore, even adopt the burst signal of same spread sign indicating number to be received from a plurality of mobile radio stations in identical frequency band simultaneously, signal and the execution Rake that also can distinguish reliably from each mobile radio station merge, and make communication quality to improve significantly.
Next, with reference to the spectrum spread communication system of Fig. 8 description according to the embodiment of the invention.
Fig. 8 is the block diagram of a wireless base station that illustrates according to a second embodiment of the present invention 300.Characteristics of the present invention are to provide a searcher unit 421 and a plurality of pilot code type (PL) type detection unit 480-1 to 480-J in a second embodiment, and those pilot code type searcher units that provide among first embodiment are provided.
Spreading code A generation unit 410, path control unit 430, tracking cell 440-1 is to 440-M, and correlation unit 450-1 is to 450-M, and pilot code type Rake (PL RAKE) merge cells 460-1 has as first to 470-N to 460-N and pilot code type (PL) data decode unit 470-1
The function that embodiment is same.
The digital received signal that searcher unit 421 input obtains to digital form from the spreading code A of spreading code generation unit 410 outputs and the burst signal that receives from mobile radio station by conversion.Searcher unit 421 calculating surpass the correlated components with spreading code A of hunting zone to determine a distribution, detect the path candidate of received signal then.The path candidate that detects send to PL type detection unit 480-1 to 480-J in case differentiation corresponding to the pilot code type of each path candidate.The data of the path candidate that indication detects send to path control unit 430 with the data of the corresponding pilot code type of indication, carry out and the first embodiment identical operations then.
That is, path control unit 430 is determined to carry out the path of following the tracks of processing from input path data and pilot code type data, gives tracking cell 440-1 to 440-M so that send instruction.Tracking cell 440-1 to 440-M carries out respectively to follow the tracks of to the path of indication and handles.Correlation unit 450-1 to 450-M determines the correlated components of received signal according to the output of corresponding tracking cell.Also have, control unit 430 issuing commands in path are given pilot code type Rake merge cells, so that from corresponding to an input correlated components the correlation unit 450-1 to 450-M in the path of same pilot code type.Pilot code type Rake merge cells 460-1 carries out Rake to 460-N to the correlated components of the multi-path of each pilot code type and merges.Each pilot code type (PL) data decode unit 470-1 is included in moving station mark symbol in this decoded signal to 470-N decoding corresponding to the signal of each pilot code type and extraction.Therefore, each pilot code type data decode unit 470-1 specifies the moving station mark numbering to 470-N.
Below the operation, PL type detection unit 480-1 of describing searcher unit 421 with reference to Fig. 8 to the operation of 480-J and path control unit 430, tracking report 440-1 to 440-M, correlation unit 450-1 to 450-M and PL RAKE merge cells 460-1 to 460-N.
In order to simplify description, suppose PL1, the pilot code type of PL2 and PL3 is distributed to three mobile radio station 200-1 respectively to 200-3, and spread spectrum is to adopt spreading code A to realize, so that at burst signal of each mobile radio station emission.Also have, suppose that searcher unit 421 is according to exporting 10 path candidates than maximum-likelihood level order.Further, suppose to provide 10 PL type detection unit 480-1 to 480-10 and provide 10 groups of tracking cell 440-1 to 440-10 and correlation unit 450-1 to 450-10.
Under a kind of like this condition, suppose that spreading code A and received signal are transfused to and searcher unit 521 output 10 paths such as s1 to s10.
Order 01 02 03 04 05 06 07 08 09 10
Path s1 s2 s3 s4 s5 s6 s7 s8 s9 s10
Offer PL type detection unit 480-1 respectively to 480-10 from data searcher unit 421 outputs, indication 10 paths, so that the pilot code type in input path is distinguished in each PL type detection unit.The homophase addition of each PL type detection unit execution pilot code type in-phase component allocating in advance by the timing of path data indication between to a coded sequence of coded sequence of the pilot code type of mobile radio station and received signal.PL type detection unit provides pilot code type with maximal correlation component and sequential to path control unit 430.
Supposing that path and pilot code type are described below in each PL type detection unit corresponds to each other.
Path S1 S2 S3 S4 S5 S6 S7 S8 S9 S10
PL?PL1PL2PL1PL3PL2PL1PL1PL2PL3PL2
According to these data, path control unit 430 sends the data in the path that will follow the tracks of to each tracking cell.That is, the path that a plurality of instructions are published so that tracking cell 440-1 follows the tracks of s1, tracking cell 440-2 follows the tracks of the path of s2, and tracking cell 440-3 follows the tracks of the path of s3 ..., tracking cell 440-10 follows the tracks of the path of s10.Correlation unit corresponding to each tracking cell is exported for the correlated components of received signal in the respective paths to spreading code A.
Moreover path control unit 430 connects corresponding to the output of the correlation unit of identical PL sign indicating number type and corresponding pilot code type Rake (PL RAKE) merge cells so that the Rake of carrying out the same paths output signal and merges.That is, because correlation unit 450-1,450-3,450-6, the correlated components of the received signal in the path of 450-7 output PL1 is so the output of each correlation unit all is connected to PL1RAKE merge cells 460-1.Because correlation unit 450-2,450-5,450-8, the correlated components of the received signal in the path of 450-10 output PL2 is so the output of each correlation unit all is connected to PL2 RAKE merge cells 460-2.Also have, because correlation unit 450-4, the correlated components of the received signal in the path of 450-9 output PL3 is so the output of each correlation unit all is connected to PL3RAKE merge cells 460-3.
Each PL RAKE merge cells 460-1 in the 460-3 by carry out Rake merge the signal that obtains by correspondence separately pilot code type (PL) the data decode unit 470-1 of pilot code type decode to 470-3.As a result, be included in moving station mark data in the decoded data and be extracted and export received signal as each mobile radio station appointment.
Like this, in spectrum spread communication system of the present invention, these a plurality of paths (multi-path) have the correlated components to the spreading code A in the searcher unit.The pilot code type in the path of each detection is distinguished in each PL type detection unit.Moreover, be to carry out for the tracking operation of every paths and the extraction of received signal correlated components according to the path data that detects.Therefore, even adopt the burst signal of same spread sign indicating number to receive from a plurality of mobile radio stations in identical frequency band simultaneously, signal and the execution Rake that also can distinguish reliably from each mobile radio station merge.Therefore, communication quality can improve widely.
As mentioned above, according to spectrum spread communication system of the present invention, for mobile radio station distributes a kind of pilot code type, and this pilot code type can be distinguished.Therefore, this burst signal can use same spreading code emission.Compare with the system according to the type classification mobile radio station of spreading code, the structure of receiving system can be simplified significantly.Also have, can both be detected for each pilot code type multi-path or a plurality of path.Therefore, even adopt the same spread sign indicating number, also can receive reliably from the signal of each mobile radio station in order to transmit.As a result, can carry out effective Rake merges so that improve voice quality significantly.

Claims (16)

1. spread spectrum communication system comprises:
A plurality of mobile radio stations, each mobile radio station use single spreading code spread spectrum emission data and on identical frequency band the emission data of emission spread spectrum as wireless signal, wherein said emission data comprise pilot code type and data, described pilot code type is different and orthogonal mutually, and distributes to described a plurality of mobile radio station respectively; With
The wireless base station is used for receiving described wireless signal from described each mobile radio station, and allows according to described wireless signal and described each mobile station communicate.
2. spread spectrum communication system according to claim 1, wherein said data comprise the identification data of described each mobile radio station.
3. the mobile radio station that uses in the spread spectrum communication system according to claim 1 and 2.
4. the wireless base station that uses in the spread spectrum communication system according to claim 1 and 2.
5. the communication means in the spread spectrum communication system comprises step:
Each emission wireless signal on identical frequency band from a plurality of mobile radio stations, wherein generate described wireless signal from the emission data, described emission data are used identical spreading code spread spectrum and comprise data and different orthogonal guide frequency sign indicating number type between described a plurality of mobile radio stations; With
Receive described wireless signal by the wireless base station, to allow based on described wireless signal and described each mobile station communicate.
6. communication means according to claim 5, wherein said data comprise the identification data of described each mobile radio station.
7. according to claim 5 or 6 described communication meanss, wherein said step of transmitting comprises step:
Use is to the described emission data of the identical spreading code spread spectrum of described a plurality of mobile radio stations; With
On described identical frequency band, launch the emission data of spread spectrum as described wireless signal to described wireless base station.
8. according to claim 5 or 6 described communication meanss, wherein said receiving step comprises step:
From described a plurality of mobile radio stations each receives described wireless signal;
Produce digital signal from described wireless signal;
According to described pilot code type from described digital signal generation pass data;
Determine the path relevant according to described path data with described digital signal; With
Component to each path detection of determining described digital signal relevant with described spreading code.
9. mobile radio station in the spread spectrum communication system that comprises a plurality of mobile radio stations and base station, described mobile radio station comprises:
Spreading part spreads is used to use spreading code spread spectrum emission data, and wherein said emission data comprise the pilot code type and the data of quadrature, and the pilot code type of described quadrature is different between described a plurality of mobile radio stations, and described spreading code is identical to described a plurality of mobile radio stations; With
Radiating portion, the emission data that are used for launching spread spectrum to described wireless base station on a frequency band are as wireless signal, and described frequency band is identical to described a plurality of mobile radio stations.
10. mobile radio station according to claim 9, wherein said data comprise the identification data of described mobile radio station.
11. a communication means of being carried out by mobile radio station in the spread spectrum communication system that comprises wireless base station and a plurality of mobile radio stations comprises step:
The spreading code spread spectrum emission data that use is identical to described a plurality of mobile radio stations, wherein said emission data comprise unique orthogonal guide frequency sign indicating number type and data; With
The emission data of launching spread spectrum to described wireless base station on identical frequency band are communicated by letter with described wireless base station according to described wireless signal to allow described mobile radio station as wireless signal.
12. communication means according to claim 11, wherein said data comprise the identification data of described mobile radio station.
13. the wireless base station in the spread spectrum communication system that comprises wireless base station and a plurality of mobile radio stations comprises:
On identical frequency band from described a plurality of mobile radio stations each receives the receiving unit of wireless transmission data, wherein said wireless transmission data comprise data and different orthogonal guide frequency sign indicating number types, described different orthogonal guide frequency sign indicating number type is distributed to described a plurality of mobile radio station respectively, and uses a single spreading code to described different orthogonal guide frequency sign indicating number type spread spectrum by described a plurality of mobile radio stations;
Produce the generation part of digital signal from described wireless transmission data;
According to the generating portion of described different orthogonal guide frequency sign indicating number type from described digital signal generation pass data;
Determine the Path Determination part relevant according to described path data with described digital signal; With
Test section at the component of each path detection of determining described digital signal relevant with described spreading code.
14. base station according to claim 13, wherein said data comprise the identification data of described mobile radio station.
15. the communication means in the described wireless base station in the spread spectrum communication system that comprises wireless base station and a plurality of mobile radio stations, described method comprises step:
From described a plurality of mobile radio stations each receives the wireless transmission data, wherein said emission data comprise different orthogonal guide frequency sign indicating number type and data, described different orthogonal guide frequency sign indicating number type is distributed to described a plurality of mobile radio station respectively, and uses a single spreading code that a plurality of described wireless transmission data are carried out spread spectrum by described a plurality of mobile radio stations;
Produce digital signal from described wireless transmission data;
According to described different pilot code type from described digital signal generation pass data;
Determine the path relevant according to described path data with described digital signal; With
Component at each path detection of determining described digital signal relevant with described spreading code.
16. communication means according to claim 15, wherein said data comprise the identification data of described each mobile radio station.
CNB021602646A 1998-03-04 1999-03-04 Spectrum spreading communication system using single spread spectrum code Expired - Lifetime CN1321505C (en)

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US20030112852A1 (en) 2003-06-19
CN1235442A (en) 1999-11-17

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